1. Field of the Invention
The present invention relates generally to a data display, and more particularly, to a data display method and a device using Active Matrix Organic Light Emitting Diodes (AMOLEDs).
2. Description of the Related Art
There is currently a continuously increasing demand for flat panel displays in the market, and thus, diverse types of display devices have been developed. In particular, due to its excellent color representation and thin implementation, AMOLEDs have entered the markets of portable phones as well as portable terminals, such as Personal Digital Assistants (PDAs), MPEG Audio Layer-3 (MP3) devices, and the like.
Organic Light Emitting Diodes (OLED) is a self-luminescence display in which, if current flows to a phosphorous or phosphorescent organic thin film, electrons and holes are bonded on an organic layer to emit light. The OLED is divided into a Passive Matrix OLED (PMOLED) and an AMOLED. The PMOLED adopts a line driving type in which light emitting elements on a whole line simultaneously emit light, and the AMOLED adopts an individual driving type in which light emitting elements individually emit light.
In the AMOLED, the brightness of the emitted light differs in accordance with the amount of current, and thus, a large amount of current is consumed when the AMOLED emits light. FIG. 1 is a graph illustrating power consumption of AMOLED according to the brightness, that is, brightness value. Referring to FIG. 1, as the brightness value becomes large, larger power consumption is made. Since the AMOLED is a self-luminescence device, unlike a Liquid Crystal Display (LCD), Red-Green-Blue (RGB) values should be lowered in order to lower the power that is consumed in the AMOLED. Accordingly, in order to adjust the display brightness provided from the system, a gamma curve according to the brightness setting that is provided by an AMOLED display provider is used.
Since the current consumption is increased when the AMOLED having the above-described characteristics emits bright light, it is essential to lower the power consumption for diverse applications of the display device. This coincides with the general requirement in the display market for efficient use of power for long time use of content in a limited power environment.
However, if an image driving voltage is collectively lowered to save the consumed power of the AMOLED, the brightness of an unwanted portion of the image is reduced deteriorating picture quality. FIG. 2 illustrates an adjustment of the brightness level of a first display screen 10 according to an AMOLED gamma curve, and shows a second display screen 20 and a third display screen 30. As illustrated in FIG. 2, if the brightness of pixels is adjusted according to the AMOLED gamma curve, the brightness of the whole screen is lowered, and thus a user's visibility is not effective.